feat: Claude Code Monitor — lanes, pipelines and a merged workspace

Internal SmartGift build of a Claude Code monitoring dashboard.

Lanes: a durable unit of parallel agent work, one per working directory,
tracked across session restarts. Managed lanes are git worktrees the
dashboard provisions and can reset or remove behind a three-check destroy
guard and a counted preflight; adopted lanes are directories you already
own and are never destroyable.

Pipelines: a lane moves through pipeline stages. A stage the agent declares
with evidence renders green; a stage inferred from the tool-event stream
renders dashed amber and never counts as done. Detection is forward-only
within a 30-minute window, and never writes the declared stage.

Workspace: one page at /run with a lane grid, the selected lane's pipeline,
and a full Claude console behind a disclosure.

plugins/ccam-devtools/skills/session-debug/SKILL.md

@@ -0,0 +1,78 @@
+---
+description: >
+  Debug a specific session by inspecting its full event chain (PreToolUse,
+  PostToolUse, Stop, SubagentStop, Compaction, APIError, TurnDuration,
+  Notification events), agent hierarchy (recursive parent/child tree with
+  subagent_type and depth), token usage with compaction baselines, workflow
+  intelligence data (orchestration DAG, error propagation by depth), and
+  session metadata (thinking_blocks, turn_count, total_turn_duration_ms).
+---
+
+# Session Debug
+
+Debug and inspect a Claude Code session from Agent Monitor data.
+
+## Input
+
+The user provides: **$ARGUMENTS**
+
+This may be:
+- A session ID to debug
+- "latest" or "last" for the most recent session
+- "errors" to find and debug the most recent errored session
+
+## Procedure
+
+1. **Identify the target session**:
+   - If session ID given: `GET /api/sessions/{id}` from `http://localhost:4820`
+   - If "latest": `GET /api/sessions?limit=1` (default sort: most recently updated first)
+   - If "errors": `GET /api/sessions?limit=10&status=error`
+
+2. **Collect full session data**:
+   - Session metadata: status, model, cwd, timestamps, duration
+   - Events: `GET /api/events?session_id={session_id}` — full event timeline
+   - Agents: `GET /api/agents?session_id={session_id}` — all agents in session
+   - Cost: `GET /api/pricing/cost/{session_id}`
+
+3. **Analyze the session**:
+
+   ### Session Lifecycle
+   - Start time → first event → last event → end time
+   - Status transitions (active → working → completed/error)
+   - Total duration and active-vs-idle time
+
+   ### Event Chain Analysis
+   - Chronological event list with timestamps and durations
+   - Identify the **critical path** (longest chain of dependent events)
+   - Flag events that took unusually long
+   - Highlight error events with full error context
+
+   ### Agent Inspection
+   - List all agents: type, task, status, duration
+   - Subagent tree visualization (parent → children)
+   - Agents that failed and their last known state
+   - Agent switching patterns (when and why new agents spawned)
+
+   ### Tool Execution Trace
+   - Every tool invocation in order with: tool name, duration, success/failure
+   - Failed tool calls with error messages
+   - Tool retry patterns (same tool called multiple times)
+
+   ### Anomaly Detection
+   - Events out of expected order
+   - Gaps in event timeline (>30s with no events)
+   - Duplicate events or agent states
+   - Token usage spikes (compaction indicators)
+
+4. **Diagnosis**:
+   - Root cause hypothesis (if errors present)
+   - Contributing factors
+   - Remediation suggestions
+
+## Output Format
+
+Present as a debug report with:
+- Session summary header (ID, status, model, duration, cost)
+- Color-coded timeline (✅ success, ❌ error, ⚠️ warning, ℹ️ info)
+- Agent tree diagram
+- Diagnosis section with numbered findings